• Resources Recycling
• /
• v.23 no.5
• /
• pp.21-27
• /
• 2014

A study on the solvent extraction for the recovery of Li from lithium-containing waste solution was investigated using $D_2EHPA$ as an extractant. The experimental parameters, such as the pH of the aqueous solution, concentration of extractant and phase ratio were observed. Experimental results showed that the extraction percentage of Li was increased with increasing the equilibrium pH. More than 50% of Li was extracted in eq. pH 6.0 by 20% $D_2EHPA$. From the analysis of McCabe-Thiele diagram, 95% of Li was extracted by four extraction stage at phase ratio(O/A) of 3.0. Stripping of Li from the loaded organic phases can be accomplished by sulfuric acid as a stripping reagent and 90 ~ 120 g/L of $H_2SO_4$ was effective for the stripping of Li. Finially, Li was concentrated about 11.85 g/L by continuous stripping process, and then lithium carbonate was prepared by precipitation method.

• Analytical Science and Technology
• /
• v.20 no.5
• /
• pp.400-405
• /
• 2007

The comparative analysis of glycerin in cosmetic samples was carried out by LC/MS and $^1H$ NMR spectrometry. For the LC/MS analysis, aqueous solution was controlled in strong basic condition with sodium hydroxide, and benzoyl chloride was added to the solution for the derivatization of glycerin. The derivative was extracted using pentane and analyzed by the LC/MS. For the $^1H$ NMR analysis, sample was directly dissolved in $D_2O$ solvent without pretreatment. The quantitative analysis of glycerin was done by $^1H$ NMR ERETIC method. The analysis results of LC/MS and $^1H$ NMR showed that the calibration curves were a good linearity with $r^2=0.9991$ in the range of 0.1 to $10{\mu}g/mL$ and $r^2=1$ in the range of 25 to $500{\mu}g/mL$, respectively.

• Clinical and Experimental Pediatrics
• /
• v.45 no.12
• /
• pp.1577-1584
• /
• 2002

Purpose : Airway inflammation is considered to be a characteristic feature of asthma, and eosinophils are recognized as the most important inflammatory cells. This study aims to assess the importance of blood eosinophil count and serum eosinophil cationic protein(ECP) levels as a noninvasive marker of bronchial hyperresponsiveness(BHR) in children with suspected asthma. Methods : This study used data from 87 subjects with asthma-like symptoms(6-18 years old). The $FEV_1$ and provocative concentration producing a 20% fall in $FEV_1(PC_{20})$ on methacholin inhalation challenge test were measured. Four groups were classified based on $PC_{20}$[Group I : <2 mg/mL; Group II : 2-8 mg/mL; Group III : 8-18 mg/mL; Group IV : (18 mg/mL], and blood eosinophil count and serum ECP levels were analyzed. In addition, subjects were classified based on the cutoff value of $PC_{20}$(BHR positive group : <18 mg/mL; BHR negative group : (18 mg/mL). Then blood eosinophil count and serum ECP level were compared between these two groups. Results : Likelihood ratio test for trends revealed a significant association between the blood eosinophil count or serum ECP level, and the degree of BHR as measured by methacholine $PC_{20}$. Blood eosinophil count or serum ECP level was significantly higher in the BHR(+) group than in the BHR(-) group. Blood eosinophil count had a positive correlation with serum ECP level. Conclusion : Blood eosinophil count and serum ECP level may be a useful non-invasive clinical marker of BHR in subjects with suspected asthma. This supports the hypothesis that BHR in asthma is a consequence of airway eosinophilic inflammation.

• Analytical Science and Technology
• /
• v.16 no.6
• /
• pp.483-487
• /
• 2003

Amitrole is well-known as a non-selective herbicide and it is able to cause contamination of driking water as well as pollution of ground water and surface water. However, it is difficult to extract from water because it has a high solubility for water whereas a low solubility for general organic solvents. This method is described for the determination of amitrole in water samples by GC/MS. After evaporation of 10 mL water sample by a vacuum evaporator, amitrole was derivatized with isobutyl chloroformate (iso-BCF) on room temperature for 15~20 min. As a result, the sensitivity for GCfMS was improved as N-isobutoxycarbonyl amitrole derivative was formed. The linearity of the calibration curve showed good as 0.997. The recoveries were obtained more than 94.9% and relative standard deviations were less than 2.8% at $1.0{\mu}g/L$, $10.0{\mu}g/L$ and $100.0{\mu}g/L$. The limit of detection showed $0.1{\mu}g/L$ with a signal-to-noise ratio (S/N) of 3.

• Food Science of Animal Resources
• /
• v.30 no.3
• /
• pp.410-418
• /
• 2010

Staphylococcus aureus is one of the major pathogens that can cause staphylococcal infection and food poisoning. In this study, we compared conventional culture methods and real-time PCR for detection of S. aureus in artificially inoculated milk, sausage, raw pork, and vegetable salad. The performance of a coagulase test for confirming S. aureus was also compared with a colony PCR test. Bulk food samples (500 g each) were artificially inoculated with S. aureus and divided into 20 samples (25 g or mL each). All samples were added to tryptic soy broth (225 mL/sample) with 10% NaCl and incubated at $37^{\circ}C$ for 24 h. After the enrichment, broth cultures were streaked onto Baird-Parker (BP) agar with egg yolk tellulite, and incubated at $37^{\circ}C$ for 24 h. In addition, 1 mL of broth cultures was collected to perform real-time PCR. Two suspicious colonies from the BP agar were picked up and plated on nutrient agar and incubated at $37^{\circ}C$ for 24 h followed, by a coagulase confirmation test and a colony PCR analysis. There were no statistical differences between culture methods and realtime PCR in food samples with low background microflora, such as milk and sausage. However, a significant statistical difference was found between the culture methods and real-time PCR for raw pork and vegetable salad. Furthermore, the colony PCR test of the presumptive colonies on BP agar for confirming S. aureus is more accurate and efficient than the coagulase test for unprocessed foods.

• Journal of the Korean Geotechnical Society
• /
• v.15 no.4
• /
• pp.85-97
• /
• 1999

For a deltaic clay in the mouth of the Nakdong river, OCR was investigated through methods using the results of field measurement, laboratory and field soil tests. As a result, OCRs were obtained around the range of 0.95 to 1.20 by analysis of field measurements, although they were estimated around the values of 0.4 to 0.7 by the results of conventional consolidation tests for the clay. From the dissipation test it was found out that the excess pore pressures scarcely existed in the clay deposit and then the soil was not in the underconsolidated condition. And the OCRs obtained through methods of Mayne(1991) and Cao et al(1996) using the piezocone test and of Mayne & Kemper(1988) using the cone penetration test were in good agreement with those of field measurement.

• Journal of Life Science
• /
• v.22 no.2
• /
• pp.192-199
• /
• 2012

This study investigated the effects of Lavandula angustifolia (L. angustifolia) aroma on the brain electrical activity evaluated by electroencephalogram (EEG) in female adults with sleep disorders. The subjects were 28 healthy female adults and their sleep disorders were classified by the Pittsburgh Sleep Quality Index. EEG electrodes were attached at the frontal (F3, F4), temporal (T3, T4), occipital (O1, O2), parietal (P3, P4), reference, and ground regions according to the International 10-20 system. Subjects were exposed to the L. angustifolia aroma for 3 min. Results showed that L. angustifolia aroma decreased the occipital and parietal alpha powers, and increased the frontal theta power and occipital beta power in subjects with good sleep quality. On the other hand, L. angustifolia aroma increased the theta power in the all cranial regions after aroma treatment in subjects with poor sleep quality. In conclusion, L. angustifolia aroma diminishes a state of wakefulness in the brain and helps individuals to fall asleep. Therefore, L. angustifolia aroma may have beneficial effect for female adults with sleep disorders.

• Korean Journal of Veterinary Research
• /
• v.13 no.1
• /
• pp.39-46
• /
• 1973

Cultural method, dark field microscopy & fluorescent antibody technique were compared for their sensitivity of the detection of leptospires from experimentally infected mice. Two groups of mice were infected with L. icterohemorrhagiae (M20) and L. australis (Ballico), and the infected blood, urine and a number of organs were subjected to the bacterial isolation. The results obtained were summarized as follows: 1. L. icterohemorrhagiae (M20) and L. australis (Ballico) in blood, urine and various tissues of experimentally infected mice were detected with a negrigible non specificity, by the fluorescent antibody technique. 2. The fluorescent antibody technique, as applied to detection of leptospires in blood, urine and various infected tissue, proved to be better than cultural method and dark-field microscopy. 3. Early detection of leptospires by fluorescent antibody technique were possible in blood at 2 days after inoculation, whereas detection of organisms in liver, spleen, lung and kidney were observed later. By means of fluorescent antibody technique, the detection of leptospires in kidney and urine was possible up to 34 days postinoculation, whereas those in other parts were impossible. 4. Fluorescent antibody reaction of leptospires were highly specific to homologous antigen rather than to heterologous one. 5. Fluorescent antibody technique may be of value in the application for the demonstration of leptospira from clinical specimens.

• Journal of the Korean Chemical Society
• /
• v.33 no.1
• /
• pp.113-119
• /
• 1989

Chelating resins containing hydrazide or triethylenetetramine side chain were prepared using a commercial cation exchage resin, Diaion WK 11, and their nitrogen contents were determined by elemental analysis. The synthesized resin, and commercial chelating resins, (Diaion-CR 10 and-CR 20) were treated with various metal chelates of which metal contents were subsequently determined by chelatometry. Sectioned beads of the resin-metal chelates were also observed using electron microprobs X-ray analyzer. To examine the catalytic activity of the resin-metal chelates, they were applied to the oxidation of various hydroxy compounds and l-ascorbic acid, and found to be effective catalysts.

• Journal of Life Science
• /
• v.16 no.3 s.76
• /
• pp.534-539
• /
• 2006

In the ozone disinfection unit process of a piston type batch reactor with continuous ozone analysis using a flow injection analysis (FIA) system, the CT values for 1 log inactivation of Cryptosporidium parvum by viability assays of DAPI/PI and excystation were $1.8{\sim}2.2\;mg/L{\cdot}min$ at $25^{\circ}C$ and $9.1mg/L{\cdot}min$ at $5^{\circ}C$, respectively. At the low temperature, ozone requirement rises $4{\sim}5$ times higher in order to achieve the same level of disinfection at room temperature. In a 40 L scale pilot plant with continuous flow and constant 5 minutes retention time, disinfection effects were evaluated using excystation, DAPI/PI, and cell infection method at the same time. About 0.2 log inactivation of Cryptosporidium by DAPI/PI and excystation assay, and 1.2 log inactivation by cell infectivity assay were estimated, respectively, at the CT value of about $8mg/L{\cdot}min$. The difference between DAPI/PI and excystation assay was not significant in evaluating CT values of Cryptosporidium by ozone in both experiment of the piston and the pilot reactors. However, there was significant difference between viability assay based on the intact cell wall structure and function and infectivity assay based on the developing oocysts to sporozoites and merozoites in the pilot study. The stage of development should be more sensitive to ozone oxidation than cell wall intactness of oocysts. The difference of CT values estimated by viability assay between two studies may partly come from underestimation of the residual ozone concentration due to the manual monitoring in the pilot study, or the difference of the reactor scale (50 mL vs 40 L) and types (batch vs continuous). Adequate If value to disinfect 1 and 2 log scale of Cryptosporidium in UV irradiation process was 25 $mWs/cm^2$ and 50 $mWs/cm^2$, respectively, at $25^{\circ}C$ by DAPI/PI. At $5^{\circ}C$, 40 $mWs/cm^2$ was required for disinfecting 1 log Cryptosporidium, and 80 $mWs/cm^2$ for disinfecting 2 log Cryptosporidium. It was thought that about 60% increase of If value requirement to compensate for the $20^{\circ}C$ decrease in temperature was due to the low voltage low output lamp letting weaker UV rays occur at lower temperatures.